OS 91 Surpass Engine Featured Engine: OS 91 Surpass

Four stroke engines tickle the fancy of many of us because they are simply “neat.” Their sound stirs the imagination, and they carry the airplane around the sky in a more realistic fashon. But they are expensive. A lot of money can be saved by buying used RC engines, if you can find a dependable used engine. I try to make all of my used engines relaible through repair, testing, and rating so you will know what you are getting before you buy.

BRAND SIZE RATING PRICE SKU DESCRIPTION
Magnum XL 70 7 $110 113  
Magnum XL 91 7 $120 115  
Magnum XL 91 8 $140 116 Has every bit as much “pinch” as an OS 91
Magnum XL 91 9 $155 114  
OS Surpass 48 7 $90 16  
OS Surpass 48 7 $95 17  
OS Surpass 70 7 $135 193  
OS Surpass 70 7- $125 198 Tested with 13x6 prop. Ran at 9,200 rpm and idled at 2,100. Compression, bearings, and transition good.
OS Surpass 91 7 $155 180  
OS Surpass 91 7 $160 178 Runs very well
OS Surpass 91 7+ $170 175 Tested with a wood 14x6 prop and got 9,750 high and 1,740 idle. Transition and bearings good.
OS Surpass 91 7 $165 196  
OS Surpass 91 7- $150 183 Tested with a 14x8 prop. Ran at 9,150 rpm and idled at 2,0030. Compression, bearings, and transition good.
OS Surpass 91 7- $150 199 Tested with 14x6 prop. Ran at 9450 rpm and idled at 2,100. Compression ,bearings, and transition good. Shows surface wear, but otherwise runs well.
OS surpass 91 9 $210 179 Bench run once for about 2 minutes.
OS Surpass 91 10 $230 145 A lot of shelf time, but is still perfect.
OS Surpass 91 10 $240 143 New in Box
OS Surpass II 91 8 $180 86  
OS Surpass 120 7 $175 204 Tested with 16x8 prop (16x6 would be better fit). Ran at 7,600 rpm and idled at 2,000. Bearings, transition, and compression good.
Saito 50 7- $105 144 Tested with 12x6 prop. Ran at 9,400 rpm and idled a 1,990. Bearings, transition, and compression good
Saito 50 7 $110 158  
Saito 56 7 $130 159  
Saito 65 7 $140 160  
Saito 72 7 $150 177  
Saito 72 7 $145 165 Tested with a 13x7 prop and got 10,320 high and idled at 1,740. Compression, bearings and transition good.
Saito 72 7+ $155 151 Tested with 13x8 prop and ran at 8,200 rpm and idled at 1,900 rpm. Transitionn, bearings, and compression excellent.
Saito 80 7+ $165 150 Tested with 13x8 prop. Ran at 9,000 rpm and idled at 1,900 rpm. Copmpression, bearings, and transition excellent.
Saito 80 7 $160 163  
Saito 91 7+ $175 146 Tested in dark so not tach readings possible. High and idle rpms excellent as well as transition, compression and bearings. Impressive.
Saito 91 8- $175 200 Tested with 14x6 prop RAN at 9,360 rpm and idoled at 1,860. Compression, bearings, and transition good. Impressive.
Saito 91 8 $180 148  
Saito 91 8 $180 154 Muffler older than engine.
Saito 100 7 $180 172  
Saito 100 7+ $190 167 Runs fantastically well. tested with a 14x8 prop and got 9,000 rpm on high and idled at 1,800 rpm.
Saito 100 8+ $220 201 Tested with a 14x6 prop.(15x6 better size) Ran at 9,900 and idled at 1,900 rpm. compression, transition, and bearings great. Impressive engine
Saito 120 7 $190 229 Tested with 16x8 prop. Ran at 7,400 rpm and idled at 1,700. Will get 1,000 rpm more with a 16x6 prop. Transition, compression and bearings good.
Saito 120 7 $195 228 Tested with 16x8 prop. Ran at 7,920 rpm and idled at 1,700. Will get 1,000 rpm more with a 16x6 prop. Transition, compression, and bearings good.
YS FZ 53 6 $125 157  
YS FZ 91 7 $175 162 Impressive engine.
YS AC 110 8 $200 170  
YS AC 120 7 $195 238  
YS FS 120 7 $200 243 Stack Exhaust
YS SF 120 7 $210 244 Bulb muffler
YS SF 120 8 $215 246  
YS SF 120 7 $205 205 Muffler and 45 degree header
YS FS 120 7+ $210 239  
YS NC 120 7 $205 237 90 header plus a muffler